/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.skatiger.jrove.compiler;

import java.io.IOException;
import java.lang.reflect.Method;
import java.util.Map;

import javax.el.ELException;
import javax.el.FunctionMapper;

import org.skatiger.jrove.JroveContext;
import org.skatiger.jrove.JroveException;
import org.skatiger.jrove.JroveHandler;
import org.skatiger.jrove.TagLibrary;
import org.skatiger.jrove.component.UIComponent;
import org.skatiger.jrove.el.CompositeFunctionMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

final class NamespaceHandler extends FunctionMapper
        implements JroveHandler {
    private static final Logger logger = LoggerFactory.getLogger(NamespaceHandler.class);
    private final TagLibrary library;
    private final Map<String, String> ns;
    private JroveHandler next;

    public NamespaceHandler(JroveHandler next, TagLibrary library, Map<String, String> ns) {
        if (logger.isDebugEnabled()) {
            logger.debug("create NamespaceHandler next  " + next);
        }
        this.library = library;
        this.ns = ns;
        this.next = next;
    }

    public void apply(JroveContext ctx, UIComponent parent) throws IOException, JroveException, ELException {
        FunctionMapper orig = ctx.getFunctionMapper();
        ctx.setFunctionMapper(new CompositeFunctionMapper(this, orig));
        try {
            next.apply(ctx, parent);
        } finally {
            ctx.setFunctionMapper(orig);
        }
    }

    @Override
    public Method resolveFunction(String prefix, String localName) {
        String uri = (String) this.ns.get(prefix);
        if (uri != null) {
            return this.library.createFunction(uri, localName);
        }
        return null;
    }

}
